Reniform Nematodes from Various Geographic Origins Uniquely Influenced Cotton Development

Greenhouse studies were conducted to assess the impact of reniform nematode (Rotylenchulus reniformis) isolates originating from nine states in the US cotton belt (TN, AL, MS, LA, TX, AR, FL, SC, and GA) on the development of cotton. Two cotton cultivars, DP 2141NR B3XF, marketed as reniform nematode resistant, and DP 2317 B3TXF, a susceptible control, were employed. Origin of the reniform nematode significantly influenced plant height, number of leaves, boll weight, chlorophyll content and plant vigor, but not photosynthesis and transpiration. While cotton plants inoculated with any of the isolates sustained negative developmental impacts in comparison with the uninoculated plants, the level of these impacts differed by the origin of the isolate. The isolates originating from the delta region (AR, MS and TN) had the most pronounced negative impacts on cotton. The development of plants inoculated with the FL, SC, TX, and LA isolates were moderately impacted while plants inoculated with the AL and the GA isolates showed the least amount of impact. Across all isolates and in comparison with the susceptible control, the resistant cultivar was taller, produced more leaves and bolls, and had superior vigor, chlorophyll content, photosynthesis and transpiration. As the ability of reniform nematode to impact cotton development can differ based on geography, results from this study implied a need for the development of niche-specific reniform nematode management methods in cotton.